Instructions / Assembly

hours in a dusty environment.
To calibrate the EP8703, you must use two
jars of standard calibration salt: one
containing a 33% solution of MgCl and the
other a 75% solution of NaCl. Both are
available for purchase from General as part
numbers HR33 and HR75.
Before beginning the calibration
procedure—which is a turnkey process but
takes at least 80 minutes to complete—you
must disable the APO function so the
instrument can remain on for more than
20 minutes.
To disable the APO function ,
power on the unit in a special way by
pressing and holding the
DEW button while
pressing the button.
Following is the calibration procedure:
1. With the unit powered on and the APO
function disabled, rotate the sensor
protection cap to open its three vents and
expose the humidity sensor to the
environment.
2. Press and hold the
DEW and F/C buttons
at the same time, and then release them.
This will cause
_ _ . 1 to appear on the
lower readout.
3. Turn the unit upside-down and insert the
sensor structure in the opening of the
33% salt bottle after removing the bottle’s
cap. The fit should be tight, with no air
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